Vector Competency of Aphis gossypii and Bemisia tabaci to Transmit Cotton Leafroll Dwarf Virus

Abstract

A new variant of cotton leafroll dwarf virus (CLRDV) (genus: Polerovirus, family: Solemoviridae) was discovered in cotton (Gossypium hirsutum L.) fields that were reported to be infested with aphids and whiteflies in southern Alabama in 2017. Prior to the confirmation of CLRDV, speculation focused on whiteflies as a potential vector of the then-unknown virus. Although the only vector reported to transmit CLRDV to cotton is the cotton aphid, Aphis gossypii (Glover), two recombinant poleroviruses have been reported recently to be transmitted by the whitefly, Bemisia tabaci (Genn.). Due to the emergence of a new CLRDV variant in the U.S., and the recent studies on recombinant poleroviruses, conflicting messages that whiteflies and/or aphids could be transmitting CLRDV have been relayed to growers and stakeholders in the Cotton Belt. The objective of this study was to determine if A. gossypii or B. tabaci (B Mitotype) transmit CLRDV to cotton. The results demonstrated that the CLRDV-AL variant was transmissible by alate and apterous morphs of A. gossypii, but not by B. tabaci. These findings emphasize the importance of screening insect vectors for the transmission of novel plant virus variants to correctly identify the vector(s) and provide growers and stakeholders with appropriate information to make informed management decisions.

Characterizing the vector competence of Aphis gossypii, Myzus persicae and Aphis craccivora (Hemiptera: Aphididae) to transmit cotton leafroll dwarf virus to cotton in the United States

“…A leaf disc assay was used to characterize the transmission parameters according to the methods of Heilsnis et al (2022) . Experimental arenas were constructed from 1.25 oz plastic food cups (Dark, Mason, MI) that were modified to contain insects and leaf discs.…”

“…In 2017, cotton leafroll dwarf virus (CLRDV) (family Solemoviridae and genus Polerovirus ) was found in Alabama causing yield loss in cotton and has since been reported in 9 states across the southeastern United States of America ( Aboughanem-Sabanadzovic et al 2019 , Avelar et al 2019 , Tabassum et al 2019 , Ali and Mokhtari 2020 , Faske et al 2020 , Iriarte et al 2020 , Price et al 2020 , Thiessen et al 2020 , Wang et al 2020 ). Three aphid species have been reported as vectors of CLRDV, but only Aphis gossypii Glover, the cotton aphid, is reported to transmit the virus to cotton ( Cauquil and Vaissayre 1971 , Michelotto and Busoli 2007 , Mukherjee et al 2016 , Heilsnis et al 2022 ). The transmission parameters have only been partially characterized for A. gossypii on cotton ( Michelotto and Busoli 2007 ).…”

Cotton leafroll dwarf disease: An enigmatic viral disease in cotton

“…Due to the presence of sweet potato whitefly (Bemisia tabaci) on cotton in the south-eastern United States, its ability to transmit CLRDV on cotton was tested. B. tabaci could neither acquire nor transmit the virus, suggesting A. gossypii is the only efficient vector transmitting CLRDV onto cotton in the United States (Heilsnis et al, 2022).…”

“…tabaci could neither acquire nor transmit the virus, suggesting A . gossypii is the only efficient vector transmitting CLRDV onto cotton in the United States (Heilsnis et al, 2022 ).…”

Prospective Alternate Hosts of an Emerging Polerovirus in Cotton Landscapes in the Southeastern United States

“…CLRDV is transmitted by the cotton/melon aphid ( Aphis gossypii Glover), which is an annual pest in the southeastern United States cotton production region [ 27 , 28 , 29 ]. Aphis gossypii transmits CLRDV to cotton plants in a circulative and non-propagative manner [ 29 ].…”